Synthesis of Primary Amines via Hydrogen Atom Transfer-Initiated Cyclization/Reduction Cascade of Unsaturated Nitriles

Org Lett. 2024 Jul 5;26(26):5467-5471. doi: 10.1021/acs.orglett.4c01739. Epub 2024 Jun 24.

Abstract

We report a hydrogen atom transfer-initiated cyclization/reduction cascade for the synthesis of primary amines from δ,ε- and ε,ζ-unsaturated nitriles. The HAT transformation employs Mn(acac)3 as a catalyst and utilizes air as an oxidant along with NaBH4 as a dual-purpose reductant toward the olefin and subsequently C═N. Aromatic and aliphatic nitriles incorporating mono-, di-, and trisubstituted olefins are substrates for the reaction. Starting materials bearing malonates are transformed into the corresponding bicyclic lactams, enabling the rapid buildup of structural complexity.